Automatic tire pump



Jan, 17, 1933. E. HOPKINS l AUTOMATIC TIRE PUMP Filed Sept. l5. 1950 2Sheets-Sheet 1 Jan. 17,1933. E HOPKMS 1,894,908

AUTOMATIC TIRE PUMP Filed Sept. 15, 1930 2 Sheets-Sheet 2 //V VEN 7'0/1"EUGENE HoPK//vs Patented Jan. 17, 1933 UNITED STATES EUGENE HOPKNS, FGLEN COVE, NEW YORK AUTOMATIC TIRE PUMP Application led September 15,1930.

lvly invention relates to pneumatic tires, and more particularly to apump and regulating device to be. inserted within the ordinaryautomobile or other vehicle tire, to automatically inflate and retainthe same at a constant pressure.

The object of the invention is to arrange an automatic air pump and anair pressure regulator that may be made separate from the inner tube, orit may be incorporated and made a part of the same, its construction andarrangement being such that the tire will automatically retain itsresiliency.

Another object of my invention is to pro- 5 vide a device that issimple, durable, reliable and efcient in its action to keep the tireinflated. The unit may be applied to any inne-r tube by the ordinaryvulcanizer, and is a device that may be readily accessible for purposesof inspection, repair, or replacement of parts or replacement as awhole, if necessary. Once the tire has been fully infiated, the devicewill be automatically actuated by the revolutions of the Wheels toretain it in proper running order. The tire, with my device appliedthereto, is self-regulating as to heat and cold, there. being no chanceof over-infiating or over-heating, either while standing or riding.

A more particular object is to provide a device that is adapted to bemade as a separate unit, and applied to any pneumatic tire. ltssimplicity and accuracy, together with the quickness that the device maybe installed, commend it to the user in preference to all other tiresnow in the market. 1t saves time, care and attention, and prevents theannoyance of the tire being refilled from time to The invention will bebetter understood from the following description, taken in connectionwith the accompanying drawings, wherein is shown what is now consideredthe e5 preferred form, while the drawings illustrate. merely someexamples of means for putting my invention into practice; its scope willbe pointed out in the specification and in the appended claims.

Further objects and advantages will be- Serial No. 481,947.

come apparent as the description of the invention is hereinafterdeveloped.

Fig. 1 is a transverse sectional view of a pneumatic tire, showing myinvention applied thereto in elevation; Fig. 2 is an enlarged transversesectional view of the inner tube and my bulb chambers showing myautomatic pump and air pressure regulator in position therein; Fig. 3 isa modified form of air pressure. regulator, showing the thin flexiblediscs thereon and detached; Fig. 4 is a view of the central tube used toinflate the high and low pressure bulb chambers; Fig. 5 is anothermodified form of air pressure regulator; Fig. 6 is still anothermodified form of the same, and Fig. 7 is a detached plan view of thespring disk for closing the valve openings shown in Fig. 5. Fig. 8 is anenlarged sectional view of the air inflow cap.

Referring to the drawings 10 shows the ordinary rim of an automobile orother vehicle, the same is provided with the ordinary metal rim 11 andthe shoe clamping member 12. The pneumatic tire 13 comprise-s an innertube 14 and an outer shoe or casing 15 enclosing the same.

l/Vithin the tire are two bulbs, one above the other, the outer onebeing the smaller of the two. Reference to these bulbs will be refer-redto as high and low pressure as a matter of convenience, relating only totheir initial action as a pumping unit. The pump that is proposed to beinserted in the inner tube 14: comprises high and low pressure bulbchambers 16 and 17 the former is of relatively large size, and is madecylindrical in shape, provided with heavy circular ribs 18, andrelatively thinner connecting wall sections 19. The high pressure bulbchamber 16 is composed of live pliable rubber and reinforced with fabriccomposition or other suitable material.

rEhe upper end of the bulb chamber 16 is locked securely againstslippage by means of the members 2O and 21, holding therebetween a fibredisc 22. The member 21 is provided with a holding linger 23 that holdsthe end 24s of the bulb chamber secure. T he member 2O is pro-vided witha suitable channel 25 which may house a suitable flat disc 26 of liverubber, or any one of the well-known varieties of flap valves known tothe trade. The member 21 has channels 27, which connect the inner partof the high pressure bulb cylinder, with the valve channel 25. The abovereferred to members are all secured together by a nut 28. v

The member 20 is provided with a tire holding disc 28, which presses onthe libre disc 22. Said member 20 has a threaded extension 29 providedwith a central bore 30, which aligns with the bore 31 in the extension32. The upper part vof such extension is provided with a suitable hollowcap 33, the latter comprising a plate 34 having perforations 35 on itsunder side, and having a threaded member 36 extending upwardly with a.beveled dome 37, the inclined sides of which are Aalso providedwithperforations 38. lnterposed between the two walls ol the cap ispacked very flowing past, without excluding passage of air under suctionforce. The Yair from the outside atmosphere is drawn through theprotective cap on valve stem 32, which cap is filled with spongysubstance acting both as an air filter and a means of escape of excessair pressure, and swelling with moisture to prevent water being drawn inwith the air. Thus it will be seen that the construction and arrangementof this cap excludes dust and dirt, also dampness, from the interior ofthe device. yet permitting air to enter through the perforatio'ns 35,through the sponge or other suitable material 39 to the dome 37, andpass down the channel 31 to the interior of the low pressure bulbchamber 17. The member 2() has a second channel 40, having a valve 41that may be regulated as to pressure vby adjusting the internal nut 42.'A The channel 40, back of the valve 41, is in communication with theduct 31. The pressure of the valve 41 may be adjusted to anypredetermined amount, and any pressure in theV inner tube in excess ofthis amount will be vented or relieved through the channel 40, and pastthe valve 41 to the exterior. `On the under side of said member 2O are aplurality of radial passages or ports 43, ex-

therein, or the tube may be of a straight tubing, then twisted toprovide length witliin the bulb 16. The lower end of said tube 44 issuitablyxconnected to the lower nozzle 46 secured to the lower valveconnecting member to be now explained.

To the lower end of the high pressure bulb chamber 16 is secured a lowpressure bulb chamber 17 of relatively smaller size, also provided Withheavy horizontal ribs 47 with thinner connecting wall sections 48; suchlow pressure cylindrical bulb chamber is composed of live rubber andfabric composition orother similar flexible material, as has beenexplained in connection with the high pressure bulb 16. The lower end ofthe high pressure bulb chamber, andthe upper end of the low pressurelbulb chamber, are held securely together by members 49 and 50, each ofthe respective ends of the bulbs are locked together with a libre disc51 interposed there- 1 between. A valve outlet device is constructed`between the high and low pressureconnection ,of the two cylinders, andmay be composed of metal or of wood fibre as will be described furtheron. The valve inlet may be constructed in any ot' a plurality of ways,the most important of which Vis herewith illustrated in `Figs. 2, 3, 5and 6. The under surfaces of members 49 and 50 may beserratedv on theirinner sides so vas to hold secure the respective ends of the two bulbchambers 16 and 17. The loweil end of thebulb chamber 17 is providedwith a suitable projection 52, which lits within a suitable fei'rule 53,which is secured within the inner tube 14.

Both the high and low pressure chambers 16 and 17 arelmolded in thedesign shown so that each bulb chamber will, when in operation withinthe tire, operate on the accordian krevolutions of the wheel'to pump in`atmospheric air, and force the same first from the low pressure bulbchamber 17, into the high pressure bulb chamber 16, and then from the Yhigh pressure chamber into the' air containing inner tube 14 of thetire. By the constantfdeflection by the revolutions of the vehiclewheel, the low pressure chamber 17 keeps adding pressure to the highpressure chamber 16. As the pressure in chamber or bulb 16 increases andbecomesV greater than the pressure in the tube, the air will pass intothe valve chamber 25 and pass thence through passes 43 into the tube,and at the same time the large bulb 16 tends to elongate and squeezedown the relatively lighter walls of the small bulb 17. As pressure fromthe air pump or tank continues, air chamber 16 aiidalso the inner tubeboth reach, for example, the standard pressure of forty pounds, but withthe result that the larger bulb 16, with its heavier walls, haselongated and compressed the smaller bulb 17, so that itbecomes-inactive. The importance of the bulb Yis construction isapparent from the fact that the ribbed Walls prevent expansion of thebulbs except in one direction, namely, length. 1n its movementlengthwise, said bulb cause the loi-v pressure chamber 17 to assume moreand more a condition of collapse, and therefore ithas opportunity to addonly little or l,times to remain central of the chamber 16.

1t may be preferable to inflate the tire or ,tires at a service stationto a practical extent before starting out on a trip, but it is not atall necessary if the tires have only a small quantity of air therein, asthe pump Will commence to act and cause the air to be compressed withinthe tire to the desired extent. But to i'ill the tire by this means, itis only necessary to drive slowly until the tires have reached theirmaximum of inflation, after which no further attention is necessary; beit hot or cold Weather, the device will automatically adjust itself.

But if refilling at the station, it is only necessary first, to removethe cap 33 and apply the valve stem (not shown) of the station supplyagainst the projection 54 of a flat plate 55 inserted across the openingin the channel 31, which Will permit the air to pass down through thetube 43 to the lov7 pressure bulb chamber 17. The air then passesthrough channels 81 in the member 50, past the flat terrible disc 57,Which is housed in channel 56, into the high pressure chamber 16. Thenwhen this member is pumped up to the standard quantity, say 40 lbs., itwill pass into the confines of the inner tube 14. lhen the tube 14 andthe high pressure bulb chamber have attained the maximum, the cap 33 isreturned to the top of the valve stem 32. rlhen as the vehicle passesover the road, the revolutions of the Wheel cause the tvvo bulbs 16 and17 to cooperate in maintaining the proper quantity of air Within thetire. The high pressure bulb 16 being now extended, and the low pressurebulb in a more or less collapsed, condition, as the Wheel passes overthe uneven places in the road the low pressure bulb chamber vsill causesuction action on the tube 44 and cause air to enter the open- 35 in thecap, be ltered by the sponge, then pass through openings 38, and fromthere pass dovvn the stem through the tube 44, to the low pressure bulbchamber 17, then through channels 81, past the flat flexible disc 57into the high pressure chamber 16, after Which it passes into the tire14. `When the inner tube 14 and the high pressure bulb 16 have attainedtheir maximum pressure, the low pressure bulb 17 will not act untilthere exists a difference in pressures.

Referring novv to Fig. 3, it Will be seen that the clamping members 58and 59 have secured to their outer sides flat flexible discs 60 and 61,as shown. As the air is forced down through the tube 44, the air forcesthe disc 61 from the lovver face, and escapes into the loiv pressurebulb chamber 17, through openings 62 which are in alignment Withchannels Which convey it to the. high pressure bulb chamber 16, if tl epressure in the high pressure bulb is such as to permit the flexibledisc GO to lift and the air to enter. T his last mentioned disc may havereinforced ends, whereby it Will at all times remain in closed position,only opening when the pressure in the upper bulb Will permit.

1n 5 is shown another form wherein the clamping members 63 and 64 clampthe respective ends of the upper and lower bulbs, each member having asuitable chamber 65 and 66 therein. In each ease, it has been foundpreferable to have the libre disc 51 interposed. between the members tooperate in connection with the flexible valves. rlhe member 63 houses,as has been noted, any one of several Well-known methods of fiippingvalve 67 that only moves as the pressure in one or the other bulbrequires. The member 64 houses the terminal of the central air inlet 78,the openings of which may be closed by a suitable spring disc 68 whichWill hold a soft cushion up against the openings and keep them closed.

In Fig. 6 is shown another form, the clamping members 69 and 70 eachbeing hollowed out so that when put together they form chamber 71. Inthis form the inlet nozzle discharges into the cent-ral chamber 71, andfrom said chamber into the lower bulb 17. Suitably secured to the innersides of each of said clamping members may be provided iiexible mushroomvalves 7 Q and 73, each having its enlarged head 74 and 75 spreadingover the opening 76 and 77, holding these respective openings in properposition until the pressure in one or the other requires the respectivevalve to function. As has been stated, these several valves compriseonly a. few of the many forms that have been used in the experiment.

After the air passes under pressure into high pressure bulb chamber 16,it continues under pressure elongating the high pressure bulb chamber16, until it exceeds the airpressure in the air containing tube 14, ashas been noted. As the high pressure bulb chamber 16 is elongated by theair pressure, it presses down on loxv pressure chamber 17, shorteningthe air pressure bulb cylinder 17, thereby reducing proportionately theaction of low pressure bulb chamber 17, eventually compressing it to apoint of complete collapse and entirely stopping its action.

lVhen the air pressure in high pressure chamber 1G exceeds the airpressure contained in tube 1-1, the Walls of the high pressure chamber1G are straightened out, or become extended, or tend to become so; andunder the high pressure, increased by the Wheel in contact with the roadunder load pressure, theair is forced from the high pressure bulbchamber 16 through valve outlet 26, into the vair containing innerk tube14.

lVhile I have herein described the form of my invention as at presentpreferred and which I consider to represent the best embodiment thereof,yet I desire to have it understood that the various forms shown are onlyillustrative and that the invention may be carried out in other waysthan that shown and described; for instance, the arrangement of thevarious valves may be of metal instead of rubber or other such flexiblematerial, as shown, or the connecting members that hold the bulbstogether and contain an inflow and an outflow valve, also the bulbs maybe modified by regular accordian plaits for the compression andexpansion eXacted of them by the revolutions over the ground of theauto- Vmobile or other wheel. Any of the forms may be used or anymodification thereof to advantage, and they are all intended to comewithin the scope of the claims.

What I claim as new and desire to protect by Letters Patent is:

1. An automatic air pressure regulator for a pneumatic tire comprising,in combination, an air chamber, means in said chamber including acollapsible pumping unit for introducing air under pressure into saidchamber, an auxiliary pressure-responsive unit for controlling theoperation of said pumping unit by controlling the degree of collapsethereof, said pressure-responsive unit also being disposed within saidchamber, and means for relieving excess pressure in said chamber. Y

2. In combination with the pneumatic tire `tube of a vehicle wheel, apair of intercommunicating hollow bulbs in said tube, one of said bulbsbeing adapted upon distortion of said tube due to continued rotation ofthe said wheel in contact with the ground or other support to forceatmospheric air into the other bulb, the interior of said other bulbbeing in communication with the interior of said tube, said first-namedbulb besaid tube, said conduit opening to the atmosphere at one endthereof and into said outer bulb at the other end thereof, a valvedpassageway between said inner tube and inner bulb,and a valvedpassageway separate and distinct from said conduit and connecting saidinner and outer bulbs.

4:. In an automatic air pump and air presthe inner tube, a conduit forintroducing air from the outside of the tire to said outer bulb, and apassage connecting the tube to said conduit and containing aspring-pressed valve adapted to permit relief of excessivey air pressurewithin the tube through said conduit@ f 5. An automatic air pump and airpressure regulator adapted to be applied to any pneumatic inner tube,comprising inner and outer bulbs, a fiber plate interposed between theends of said bulbs, plates having serrated faces for clamping andholding the bulbs together, means for controlling the passage o-f airunder pressure from one to the other bulb, means for controlling thepassage of air under pressure from the inner bulb to the inner tube, aconduit for admitting air to the outer bulb, and a valved bypass betweensaid conduit and the inner tube.

6. In combination with an air chamber containing inner and outercompressible members disposed transversely of said air chamber, saidouter member constituting an intermittently operable pump, valved meansfor controlling passage of airunder pressure from the pump to the innermember and from the inner member to the air chamber, and inlet means forair from the atmosphere into said pump.

7. An automatic air pump and air pres-V sure regulator adapted to besecurely retained in predetermined relationship to and' within the innertube of a pneumatic tire, comprising two Y substantially cylindricalbulbs of different sizes, said bulbs being interconnected and expansibleand contractible without losing their cylindrical character, plates, andclamps containing valves and securing said bulbs together, means forintroducing filtered air into one of said bulbs, a' valved passagewayextending from the other of said bulbs to said tube, said bulbs beingoperated by distortion of the tire upon continued revolution, on theground or other support, of the wheel upon which said tire is mounted;and means for relieving excessive pressure within said tube through theaforesaid means.

8. n combination with a pneumatic tire of a vehicle wheel, inner andouter intercominunieating bulbs disposed in said tire, said outer bulbbeing adapted upon distortion of said tire due to continued rotation ofsaid wheel in Contact with the ground or other support to force air intosaid inner bulb, said outer bulb being rendered inoperative when thepressure in said inner bulb reaches a predetermined amount.

9. An automatic air pump and air pressure regulator adapted to beappliedto any inner pneumatic tube, comprising inner and outer bulbs, a liberplate interposed between the bulbs, a Clamping plate on each side ofsaid liber plate, said clamping plates being provided with alinedpassageways for the passage of air from one to the other of said bulbs,flexible disc valve means associated with said ducts, a conduit foradmitting air to the outer bulb, anda valved by-pass between saidoonduit and the inner tube.

Signed at Glen Cove, in the county of Nassau and State of New YorkSeptember A. D.

EUGENE HOPKINS.

